White 99 vs Black 28
White starts from setup 99 (BQNRNKRB), Black from setup 28 (NBQNRKBR). In the encyclopedia since 2026-10-21: neither side starts better.
|cp| ≤ 5 at 400M · 800M · 1.6B · 4B nodes, two independent engines agree
How to play with different setups
White sets up the pieces by position No. 99, Black by position No. 28, mirrored on their own side; the pawns stand as usual.
Moves as usual: White starts; everything else follows the Chess960 rules.
The two setups
White: setup #99 B Q N R N K R B
King on the f-file, rooks on d, g, queen on the b-file; one bishop starts in a corner; the knights start on central files. Castling follows the Chess960 rule: king and rook end on the classical squares. In ordinary symmetric play setup 99 gives White +0.17 (Morozov Balance Index, 400M nodes).
Black: setup #28 N B Q N R K B R
King on the f-file, rooks on e, h, queen on the c-file; no bishop starts in a corner; the knights start away from the centre. Castling follows the Chess960 rule: king and rook end on the classical squares. In ordinary symmetric play setup 28 gives White +0.25 (Morozov Balance Index, 400M nodes).
Why the pair is balanced
At the deepest rungs (400M, 800M, 1.6B nodes) the evaluation never left ±3 centipawns of equality, reaching search depth 54.
Admission rule: |cp| ≤ 5 at four budgets up to 4 billion nodes, no one-sided drift along the ladder, and confirmation by two independent engines — Berserk and Lc0 — each below its own median on symmetric positions. The same corridor is required at every deeper budget (8 G, 16 G) at which the pair has been evaluated.
The shallow rungs agreed early: from 100 thousand to 128 million nodes the evaluation never left ±12 cp.
For comparison, in symmetric play setup 99 gives White +0.17 and setup 28 gives White +0.25: with both sides on the same rank the first move is worth something. In this pair Black's own setup absorbs that edge completely.
White is not forced into a single path: the best first move is c4, and 3 first moves are within 10 cp of it.
Along the engine's main line (30 moves) the evaluation stayed within ±20 cp the whole way: the balance holds as the pieces come out, not only on move one.
Engine self-play agrees: 10 games, White won 0, drawn 10, Black won 0 (White scored 50.0%).
Verification ladder
Nine independent searches of the starting position, each with a larger node budget. Evaluation in centipawns from White's point of view.
| Stage | Nodes | Depth | Eval, cp | Main line |
|---|---|---|---|---|
| S0 | 100 000 | 16 | +4 | 1. c4 f6 2. b3 Bf7 3. O-O O-O 4. g3 Bg6 |
| S1 | 500 000 | 19 | +4 | 1. c4 f6 2. Qc2 c6 3. O-O Nc7 4. g3 h5 |
| S2 | 2 000 000 | 24 | +12 | 1. c4 f6 2. b3 c6 3. g3 d5 4. cxd5 cxd5 |
| S3 | 8 000 000 | 30 | +11 | 1. c4 f6 2. b3 d5 3. cxd5 c6 4. dxc6 Bxh2 |
| S4 | 32 000 000 | 34 | +9 | 1. c4 f6 2. Qc2 c6 3. g3 h5 4. b3 Bh7 |
| S5 | 128 000 000 | 41 | 0 | 1. c4 f6 2. Qc2 c6 3. g3 h5 4. b3 Bh7 |
| S6 | 400 000 000 | 44 | 0 | 1. c4 f6 2. Qc2 c6 3. g3 h5 4. d4 Bh7 |
| S7 | 800 000 000 | 50 | -3 | 1. c4 f6 2. Qc2 c6 3. g3 Nc7 4. b3 h5 |
| S8 | 1 600 000 000 | 54 | 0 | 1. c4 f6 2. Qc2 c6 3. g3 Nc7 4. d4 d5 |
Deep verification
The search ladder reaches 1.6 billion nodes; admission needs a 4-billion rung and two further engines on top of that. Beyond even that, every pair was re-checked at budgets up to ten times larger and in thousands of self-play games. This section shows what each check returned for this pair.
| Nodes | Eval, cp |
|---|---|
| 4 000 000 000 | 0 |
| 8 000 000 000 | not checked |
| 16 000 000 000 | not checked |
This pair stays within the ±5 cp corridor up to 4 000 000 000 nodes.
Independent engines, run on the same position:
- Berserk 14: 0
- Lc0 0.32.1: +5
Independent confirmations: 3 of 3. An engine counts as confirming when its reading of the pair is closer to equality than its own reading of a typical symmetric Chess960 position (+10 for Berserk, +18 for Lc0). Where only one engine confirms, the pair is balanced according to that engine alone, and this page says so.
Own weight of each setup, measured against the classical array: White +129, Black +79, difference +50. A balanced pair needs White's setup to be weaker by about the price of the first move.
Extended self-play: 10 games, 0 White wins, 10 draws, 0 Black wins, White scored 50.0%.
Best first moves
The 3 best first moves for White, searched together at 400 000 000 nodes.
| # | Eval, cp | Depth | Main line |
|---|---|---|---|
| 1 | -2 | 43 | 1. c4 f6 2. b3 d5 3. cxd5 c6 4. g3 cxd5 5. Ncd3 e5 |
| 2 | -6 | 43 | 1. b3 d5 2. g3 f6 3. d4 c6 4. e4 Bf7 5. O-O O-O |
| 3 | -9 | 42 | 1. g3 f6 2. b3 d5 3. d4 c6 4. e4 dxe4 5. c4 b5 |
Main-line play-out
30 moves, 5 000 000 nodes per half-move. Largest |evaluation| 20 cp, mean 9.6 cp, final -7 cp.
| # | White | cp | Black | cp |
|---|---|---|---|---|
| 1 | c4 | +15 | f6 | +7 |
| 2 | b3 | +7 | d5 | +7 |
| 3 | cxd5 | -1 | c6 | -10 |
| 4 | g3 | -19 | cxd5 | -17 |
| 5 | f4 | -19 | Qh3+ | -18 |
| 6 | Bg2 | -15 | Qxh2 | -12 |
| 7 | Qd3 | -9 | Qh5 | -13 |
| 8 | Rh1 | -10 | Qf7 | -10 |
| 9 | Nf3 | -17 | h6 | -20 |
| 10 | Nh4 | -13 | Bh7 | -13 |
| 11 | Qxd5 | -8 | g5 | -18 |
| 12 | fxg5 | -7 | hxg5 | -6 |
| 13 | Nf5 | -7 | Qxd5 | -8 |
| 14 | Bxd5 | -9 | Nb6 | -11 |
| 15 | Be4 | -6 | Kf7 | -6 |
| 16 | Kg2 | -11 | Bg6 | -7 |
| 17 | Bd3 | -10 | e6 | -12 |
| 18 | Ne3 | -12 | Nd7 | -9 |
| 19 | Rxh8 | -19 | Rxh8 | -16 |
| 20 | b4 | -10 | Nc6 | -10 |
| 21 | Bxg6+ | -19 | Kxg6 | -9 |
| 22 | Nd3 | -8 | Rd8 | -6 |
| 23 | a4 | -2 | f5 | -5 |
| 24 | Rc1 | -9 | a6 | -8 |
| 25 | Bc3 | -9 | Nce5 | -9 |
| 26 | Nc5 | -4 | Nxc5 | 0 |
| 27 | bxc5 | 0 | Nd7 | -5 |
| 28 | Bb2 | -8 | Rc8 | -3 |
| 29 | Ba3 | -3 | b6 | -3 |
| 30 | Nc4 | -6 | b5 | -7 |
Engine self-play
10 games at 500 000 nodes per move: White won 0, drawn 10, Black won 0 — White scored 50.0%. Average length 41.4 moves.
Sample game 1 (1/2-1/2)
1. c4 h5 2. g3 f6 3. b3 c6 4. f4 h4 5. Nf3 hxg3 6. hxg3 d5 7. Nd3 Nb6 8. Nf2 dxc4 9. Nh4 Bf7 10. Be4 Bxf4 11. Bf5 Qc7 12. Rh1 Bh6 13. Kg2 e6 14. Bg6 cxb3 15. Bxf7 bxa2 16. Ng6+ Kxf7 17. Nxh8+ Rxh8 18. Qxa2 c5 19. e4 Nc6 20. Ng4 Nd7 21. d4 Nxd4 22. Bxd4 cxd4 23. Rxd4 b6 24. Qc4 Qxc4 25. Rxc4 Nc5 26. Nxh6+ gxh6 27. Ra1 Ra8 28. Rb4 a5 29. Rxb6 Nxe4 30. Rb7+ Kg6 31. Rb6 e5 32. Re1 Kf5 33. Rb3 Nc5 34. Rb5 Nd3 35. Re3 Rd8 36. Rxa5 h5 37. Ra3 Nb4 38. Rf3+ Kg6 39. Ra5 Kg5 40. Rf2 Kg6 41. Kh3 Kg5 42. Kg2 Nd5 43. Rfa2 Ne7 44. Kh3 Ng6 45. R2a3 Rd2 46. R5a4 Rd8 47. Ra8 Rd1 48. R8a4 Rh1+ 49. Kg2 Rb1 50. Kh3 Rh1+ 51. Kg2 Rd1 52. Ra8 Rd2+ 53. Kh3 e4 54. Ra2 Rd3 55. R8a5+ Ne5 56. Re2 Rd4 57. Rea2 h4 58. R2a4 Rd3 59. Rxe4 Rxg3+ 60. Kh2 Rc3 61. Rexe5+ fxe5 62. Rxe5+
Sample game 2 (1/2-1/2)
1. e4 c5 2. O-O e5 3. g3 f6 4. b4 c4 5. Ng2 Bf7 6. Ne3 b5 7. d4 O-O 8. Ne2 a6 9. dxe5 fxe5 10. Bg2 Nb6 11. Kh1 Nc6 12. a3 Ne7 13. Qc1 Bh5 14. f3 Qc6 15. Qd2 Kh8 16. Ng4 Qe6 17. Ne3 Qh6 18. Bb2 Rd8 19. Nc3 Bf7 20. Bc1 Be6 21. g4 Bg8 22. Qf2 Qf6 23. Nf5 Nxf5 24. exf5 d5 25. f4 Bc7 26. Qc5 Rc8 27. Qg1 Qh4 28. Bxd5 Nxd5 29. Nxd5 Bxd5+ 30. Rxd5 exf4 31. Bxf4 Bxf4 32. Rxf4 Rcd8 33. Rxd8 Rxd8 34. Qf2 Qh3 35. Qe1 h6 36. f6 gxf6 37. Rxf6 Qxg4 38. Qe5 Rd1+ 39. Rf1+ Kg8 40. Qe8+ Kg7
Play it in the CH960 app
Open this page on a phone with the CH960 app installed, or find pair 99 / 28 in the app's encyclopedia, then choose how to play.
- Local game — two players on one device, with a clock.
- With a mentor — a clearly labelled training bot with hints, at your level.
- Challenge a friend — an online game by link; both players get the same pair, colours swap on rematch.
Play this pair against the computer, right here Play a friend
FEN (Shredder, castling rights by rook files): nbqnrkbr/pppppppp/8/8/8/8/PPPPPPPP/BQNRNKRB w DGeh - 0 1
Mirror twin: White 851 vs Black 940 — a different position (castling squares are fixed), not evaluated by the search.
Current place in the live balance rating: 412.